Buffalo Patents LLC v. OnePlus Technology Shenzhen Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Buffalo Patents, LLC (Texas)
  • Defendant: OnePlus Technology (Shenzhen) Co., Ltd. (People's Republic of China)
  • Plaintiff’s Counsel: Antonelli, Harrington & Thompson LLP
• Case Identification: 6:22-cv-00421, W.D. Tex., 04/27/2022
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation and may be sued in any judicial district pursuant to 28 U.S.C. § 1391(c)(3).
• Core Dispute: Plaintiff alleges that Defendant’s smartphones infringe patents related to hybrid display technology and intelligent message recognition systems that utilize shared language models.
• Technical Context: The technologies at issue concern the physical construction of curved smartphone displays and the software architecture for multi-modal input systems, such as voice and handwriting recognition.
• Key Procedural History: The complaint alleges Defendant had pre-suit notice of U.S. Patent No. 6,856,086 via a letter dated November 26, 2021. Subsequent to the filing of this complaint, Inter Partes Review (IPR) proceedings were concluded for the other two patents-in-suit. On April 9, 2025, a certificate was issued for IPR2023-01386 disclaiming claims 1-12 of U.S. Patent No. 6,904,405. On April 7, 2025, a certificate was issued for IPR2023-01387 disclaiming claims 1-16 and 19 of U.S. Patent No. 8,204,737. The complaint asserts claim 7 of the ’405 patent and claim 13 of the ’737 patent, both of which have now been disclaimed.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,856,086 - "Hybrid Display Device," issued February 15, 2005

The Invention Explained

• Problem Addressed: The patent’s background section describes the difficulty of properly aligning lightweight, flexible polymeric substrates used in large-area displays, particularly when both substrates are produced using roll-to-roll manufacturing processes, and the need to protect such displays from moisture and oxygen ('086 Patent, col. 1:36-44).
• The Patented Solution: The patent discloses a "hybrid" display device that combines a panel with a rigid substrate (e.g., glass) and a second panel with a flexible substrate (e.g., a plastic film) ('086 Patent, Abstract; col. 2:5-9). The flexible panel can be manufactured using a cost-effective roll-to-roll process, while the rigid panel is fabricated separately and then combined with the flexible panel using a high-precision "pick and place" operation, intended to solve the alignment problems inherent in all-flexible designs ('086 Patent, Abstract).
• Technical Importance: This hybrid manufacturing approach was aimed at enabling the production of large, lightweight, and durable displays for the growing market of portable electronic devices by combining the dimensional stability of glass with the manufacturing advantages of flexible films ('086 Patent, col. 1:31-35).

Key Claims at a Glance

• The complaint asserts at least independent Claim 1 (Compl. ¶20).
• The essential elements of Claim 1 are:
  • A display device comprising a front panel and a back panel with a light control material therebetween,
  • wherein one of the panels has a rigid substrate and the other of the panels has a flexible substrate.

U.S. Patent No. 6,904,405 - "Message Recognition Using Shared Language Model," issued June 7, 2005

The Invention Explained

• Problem Addressed: The patent addresses inefficiencies in multi-modal input systems where training is tied to a specific recognizer (e.g., speech or handwriting). Correcting an error in one mode did not improve the other, and conventional language models lacked global contextual understanding, limiting recognition accuracy ('405 Patent, col. 3:46-4:32).
• The Patented Solution: The invention describes a system using multiple recognizers (e.g., for speech and handwriting) that access a "shared language model" ('405 Patent, Abstract). The core concept is that when a user corrects a misrecognition from one input type, the resulting training data updates the shared language model, which in turn improves the accuracy of the other recognition types that also rely on that shared model ('405 Patent, col. 4:5-12).
• Technical Importance: This technology sought to unify the user training experience across different input methods, making systems more intelligent and efficient by allowing improvements in one modality to benefit others ('405 Patent, Abstract).

Key Claims at a Glance

• The complaint asserts at least independent Claim 7 (Compl. ¶33).
• The essential elements of Claim 7 are:
  • A method for performing message recognition with a shared language model,
  • (a) performing message recognition of a first type (e.g., speech) using the shared language model and a first model specific to that type (e.g., an acoustic model);
  • (b) performing message recognition of a second type (e.g., handwriting) using the shared language model and a second model specific to that type (e.g., a handwriting model); and
  • (c) training the shared language model in response to a user correction of an error from either type, thereby improving the accuracy of both types of message recognition.

Multi-Patent Capsule: U.S. Patent No. 8,204,737

• Patent Identification: U.S. Patent No. 8,204,737, "Message Recognition Using Shared Language Model," issued June 19, 2012 (Compl. ¶48).
• Technology Synopsis: As a continuation in the same family as the ’405 patent, this patent refines the concept of multi-modal recognition systems. It describes a method where a device receives distinct inputs like freehand stylus manipulation and audio from a microphone, selects a specific user message model from a plurality of available models, adjusts a local language model based on that selection, and then generates converted text data using the adjusted language model in conjunction with input-specific models ('737 Patent, Abstract).
• Asserted Claims: The complaint asserts at least independent Claim 13 (Compl. ¶51).
• Accused Features: The complaint alleges that the Gboard application's ability to handle voice and handwriting, utilize personalized user profiles (e.g., "Personal" and "Work"), and adjust its language model based on user input and profile selection infringes this patent (Compl. ¶¶53-65).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are OnePlus smartphones, with the OnePlus 9 Pro 5G cited as an exemplary product, that include either (1) curved or flexible OLED displays for the ’086 patent, or (2) the Gboard application or similar virtual keyboard technology for the ’405 and ’737 patents (Compl. ¶19, ¶32, ¶50).

Functionality and Market Context

• Regarding the ’086 patent, the complaint focuses on the display's physical structure. It alleges the OnePlus 9 Pro 5G uses a "Curved Screen Flexible OLED display panel" that is manufactured on a flexible plastic substrate, allowing it to bend around the phone's edges. This flexible component is then protected by a rigid outer layer of "Corning® Gorilla® Glass" (Compl. ¶¶23, 25; Compl. p. 7).
• Regarding the ’405 and ’737 patents, the complaint focuses on the functionality of the Gboard application, identified as the default virtual keyboard on the accused smartphones (Compl. ¶36). The accused functionality includes Gboard’s capacity to perform both voice-to-text and handwriting-to-text conversion (Compl. ¶36). The complaint alleges Gboard uses a shared "n-gram language model" and an "on-device personalization" feature that learns from user input to train and improve the language model's predictions (Compl. ¶36, ¶43). The complaint further points to the Android operating system's feature allowing users to select between "Personal" and "Work" profiles, which it alleges constitutes the selection from a "plurality of user message models" (Compl. ¶58; Compl. p. 38). The screenshot on page 38 of the complaint shows the user interface for selecting between a "Personal" and "Work" profile (Compl. p. 38).

IV. Analysis of Infringement Allegations

6,856,086 Infringement Allegations

Identified Points of Contention

• Scope Questions: A central question may be the definition of a "panel." Does the term, as used in the patent, refer to a single layer like the cover glass, or must it be a multi-layer, independently fabricated assembly? The complaint's theory appears to equate the single-layer "cover glass" with the claimed "front panel" having a "rigid substrate" (Compl. ¶23).
• Technical Questions: The infringement theory rests on mapping the integrated structure of a modern smartphone display onto the patent's concept of two distinct panels being combined. A question for the court will be whether an assembly where a flexible display module is covered by a rigid protective glass fits the claimed architecture of a "front panel" and a "back panel," one rigid and one flexible. The diagram on page 9 of the complaint illustrates the layered structure of an OLED, which the complaint maps to the claimed elements (Compl. p. 9).

6,904,405 Infringement Allegations

Identified Points of Contention

• Scope Questions: The interpretation of "training the shared language model" will be critical. Does Gboard’s personalization feature, which may update a user-specific dictionary or profile, constitute "training" of the core, underlying "shared language model" as required by the claim? A screenshot on page 31 of the complaint shows word suggestions during handwriting, which plaintiff presents as a mechanism for user correction that allegedly trains the model (Compl. p. 31).
• Technical Questions: The complaint alleges that training in one mode improves accuracy in the other. A key evidentiary question will be whether the accused Gboard software actually functions this way. The diagram on page 22 of the complaint, explaining end-to-end models, is used to support the existence of a single, trainable model for multiple inputs (Compl. p. 22).

V. Key Claim Terms for Construction

Term: "a front panel" and "a back panel" (’086 Patent, Claim 1)

• Context and Importance: The infringement case for the ’086 patent depends on whether the accused device’s integrated display structure can be conceptually separated into the two distinct "panels" claimed in the patent. The defendant may argue its product is a single, unified flexible display assembly with a protective cover, not two separate panels.
• Intrinsic Evidence for a Broader Interpretation: The patent claims do not narrowly define the composition of a "panel," stating only that one "has a rigid substrate" and the other "has a flexible substrate," which could allow for various structural configurations ('086 Patent, col. 24:20-23).
• Intrinsic Evidence for a Narrower Interpretation: The specification repeatedly describes the manufacturing process as fabricating the rigid and flexible panels separately and then combining them via a "pick and place operation" ('086 Patent, Abstract; col. 2:55-58). This suggests the "panels" are discrete, pre-fabricated components, a structure potentially different from the accused product's integrated assembly.

Term: "training the shared language model" (’405 Patent, Claim 7)

• Context and Importance: Infringement of the method claim hinges on whether the accused Gboard software performs this specific action. Practitioners may focus on whether Gboard's "personalization" feature, which adapts to a user's typing patterns, meets the technical and legal definition of "training" the underlying language model itself.
• Intrinsic Evidence for a Broader Interpretation: The patent describes training as adapting a model in response to user correction, without specifying the precise mechanism. It states that "the syntactic model" can be adapted "in accordance with the modification to the selection" made by a user ('405 Patent, col. 18:59-62).
• Intrinsic Evidence for a Narrower Interpretation: A defendant may argue that "training" in the context of the patent implies a fundamental alteration of the core language model's parameters, not merely the creation of a user-specific dictionary or profile that acts as an overlay. The patent’s focus on adapting the "syntactic model" could be argued to require more than simple word-list augmentation ('405 Patent, col. 18:59-60).

VI. Other Allegations

Indirect Infringement

The complaint alleges inducement, stating that OnePlus took active steps to encourage infringement by customers through actions such as "advising or directing customers" and "distributing instructions that guide users to use the accused products in an infringing manner" (Compl. ¶72). It also alleges contributory infringement on the basis that the accused display structures and virtual keyboard features are specially designed to be used in an infringing way and are not staple articles of commerce suitable for substantial non-infringing use (Compl. ¶¶87-89).

Willful Infringement

The complaint alleges willful infringement based on pre-suit and post-suit knowledge. For the ’086 patent, it alleges knowledge as of a November 26, 2021 notice letter (Compl. ¶27, ¶91). For the ’405 and ’737 patents, knowledge is alleged from the date of notification of the lawsuit (Compl. ¶92). Willful blindness is also alleged based on a purported "policy or practice of not reviewing the patents of others" (Compl. ¶94).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue for the ’086 patent will be one of structural definition: can the integrated assembly of a modern flexible smartphone display, which is protected by a rigid glass cover, be construed to meet the claim elements of two distinct components—"a front panel" with a rigid substrate and "a back panel" with a flexible substrate—as described in the patent?
• A key evidentiary question for the ’405 and ’737 patents will be one of functional operation: does the accused Gboard software’s "personalization" feature perform the claimed step of "training the shared language model" in a manner that demonstrably improves the accuracy of both the speech and handwriting recognition modalities, or is the functional improvement isolated to the mode being used?
• A threshold procedural question for the counts involving the ’405 and ’737 patents is one of claim viability: given that the specific independent claims asserted in the complaint (Claim 7 of the ’405 patent and Claim 13 of the ’737 patent) were disclaimed in IPR proceedings that concluded after the complaint was filed, what legal and factual basis remains for pursuing these infringement claims?